Characterization of Posidonia Oceanica Seagrass Aerenchyma through Whole Slide Imaging: A Pilot Study

Characterizing the tissue morphology and anatomy of seagrasses is essential to predicting their acoustic behavior. In this pilot study, we use histology techniques and whole slide imaging (WSI) to describe the composition and topology of the aerenchyma of an entire leaf blade in an automatic way combining the advantages of X-ray microtomography and optical microscopy. Paraffin blocks are prepared in such a way that microtome slices contain an arbitrarily large number of cross sections distributed along the full length of a blade. The sample organization in the paraffin block coupled with whole slide image analysis allows high throughput data extraction and an exhaustive characterization along the whole blade length. The core of the work are image processing algorithms that can identify cells and air lacunae (or void) from fiber strand, epidermis, mesophyll and vascular system. A set of specific features is developed to adequately describe the convexity of cells and voids where standard descriptors fail. The features scrutinize the local curvature of the object borders to allow an accurate discrimination between void and cell through machine learning. The algorithm allows to reconstruct the cells and cell membrane features that are relevant to tissue density, compressibility and rigidity. Size distribution of the different cell types and gas spaces, total biomass and total void volume fraction are then extracted from the high resolution slices to provide a complete characterization of the tissue along the leave from its base to the apex

Perspektiven der Nutzung von Methanhydraten als Energieträger – Eine Bestandsaufnahme

Methane hydrates are the largest existing carbon resource, and their broad geographic distribution, especially in comparison to oil and conventional gas, make them a promising future source of energy. On the other hand, there is a danger of forcing the greenhouse effect in the event of a release of methane in the atmosphere as well as causing a destabilisation of the oceanic sediments. Also the technical difficulties in the extraction of methane are not yet fully resolved. Nevertheless, the research on methane hydrates has been forced both based on political as well as economic considerations in recent years and methane hydrates have practical advantages, which make them a noteworthy transitional solution on the way to a renewable energy based future energy supply. The knowledge of the potentials and risks of methane hydrates, however, is still poor; especially in the German-speaking public and policy. This deficiency will be solved by a focused analysis of the current state of research and an outlook, based on the most important findings.

Volumetric Cell-and-Portal Generation

International audienceWe present an algorithm to generate a cell-and-portal decomposition of general indoor scenes. The method is an adaptation of the 3D watershed transform, computed on a distance-to-geometry sampled field. The watershed is processed using a flooding analogy in the distance field space. Flooding originates from local minima, each minimum producing a region. Portals are built as needed to avoid the merging of regions during their growth. As a result, the cell it deals with parametric curves, implicit surfaces, volumetric data and polygon soups in a unified way

ENTRE PLÁTANOS [Material gráfico]

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 201

A New Method to Address Unmet Needs for Extracting Individual Cell Migration Features from a Large Number of Cells Embedded in 3D Volumes

Background: In vitro cell observation has been widely used by biologists and pharmacologists for screening molecule-induced effects on cancer cells. Computer-assisted time-lapse microscopy enables automated live cell imaging in vitro, enabling cell behavior characterization through image analysis, in particular regarding cell migration. In this context, 3D cell assays in transparent matrix gels have been developed to provide more realistic in vitro 3D environments for monitoring cell migration (fundamentally different from cell motility behavior observed in 2D), which is related to the spread of cancer and metastases. Methodology/Principal Findings: In this paper we propose an improved automated tracking method that is designed to robustly and individually follow a large number of unlabeled cells observed under phase-contrast microscopy in 3D gels. The method automatically detects and tracks individual cells across a sequence of acquired volumes, using a template matching filtering method that in turn allows for robust detection and mean-shift tracking. The robustness of the method results from detecting and managing the cases where two cell (mean-shift) trackers converge to the same point. The resulting trajectories quantify cell migration through statistical analysis of 3D trajectory descriptors. We manually validated the method and observed efficient cell detection and a low tracking error rate (6%). We also applied the method in a real biological experiment where the pro-migratory effects of hyaluronic acid (HA) were analyzed on brain cancer cells. Using collagen gels with increased HA proportions, we were able to evidence a dose-response effect on cell migration abilities. Conclusions/Significance: The developed method enables biomedical researchers to automatically and robustly quantify the pro- or anti-migratory effects of different experimental conditions on unlabeled cell cultures in a 3D environment. © 2011 Adanja et al.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Protection, Feud and Royal Power: Violence and its Regulation in English Law, c. 850 – c. 1250.

The thesis analyses the change in the way that violence was addressed in English law between the late ninth and early thirteenth centuries. It attempts to explain how a system largely based on feud, in which violence was a matter primarily for the parties involved, became one in which all serious violence was punished by the crown as crime. It does so through the examination of all the relevant legal material in the period: mostly royal law-codes and private legal compilations alongside more limited records of real-life cases. The central argument is that the concept of protection – or “protective power” – is crucial to understanding both how violence was regulated as a whole and how royal jurisdiction over violence grew. It emphasises not just royal jurisdiction but the real power that was exercised by other parties such as lords, churches, guilds and kindreds. The thesis is split into two parts, divided chronologically by the Norman conquest of England in 1066. Part one begins by assessing the situation at the beginning of this period, outlining the core elements by which a case of homicide would be settled in the system of feud. It criticises the arguments for the introduction of a royal crime of homicide under the Anglo-Saxon kings, arguing instead that the core elements of feud remained relatively unchanged before 1066. The second chapter then examines the ways in which royal jurisdiction over violence did advance in this period, and finds that these almost invariably involved the extension of specific limited protections, such as that which made violence in a house an offence punishable by the king. This picture of expanding royal jurisdiction is combined with the evaluation of the significance of feud from the first chapter to produce a new model of the regulation of violence in pre-conquest England. The third chapter applies these findings to the wider debate about the distribution of legal power under the Anglo-Saxons. It concludes that a misunderstanding of the role of protection has, in part, led historians to underestimate the significance of the powers exercised by ecclesiastical institutions, lords and free kindreds, skewing assessments of legal power heavily in the king’s favour. Part two opens with an assessment of when we can first securely demonstrate the existence of a royal prohibition of homicide. Using a variety of sources it identifies a significant shift at around the time of the Assize of Clarendon in 1166. The fifth chapter looks at a number of possible legal mechanisms that might have contributed to the shift from a system of protections to a general royal prohibition on violence. The development of the murder fine; the introduction of the concept of infamy for those defeated in judicial duels; the significance of the protection inhering in charters; and the possibility that specific royal protections merged and expanded into a general peace are all examined. The picture that emerges is once again one in which protective power plays a major role. The final chapter looks at wider ideological trends, such as the Peace Movement and the representation of crime as treachery to the king, examining the likelihood of their influencing legal developments. It argues that the ideal of a general peace against violence, which was central to the Truce of God, may well have been important in twelfth-century England. Overall, it is argued that, throughout the period, royal jurisdiction over violence increased through the expansion of royal protective power within a wider system of protections. When that expansion reached a point where the system was wholly dominated by royal protections, however, protection was swiftly replaced by a general prohibition of “violent crime”

la Réalité Augmentée: émission Utopia (RTBF-radio)

info:eu-repo/semantics/publishe